Figure REF  demonstrates a 2D visualization of the process of pose optimization by the three methods. The plots show the progressive evolution of particle sets over iteration steps. The 6D particle sets are embedded in 2D using sparse random projection [1]}. Starting with the same particle set, the three methods exhibit different exploration behaviors. PFO is able to explore a relatively large range but the particle utilization is low. PSO quickly gets stuck in a local optimum when initialized far from the optima. Our method addresses both issues and results in a much better local optimum.
